Drill-bit.



PATENTED SEPT. s, 1908.

F. W. PARSONS.

DRILL BIT.

APPLICATION FILED JAN. 7, 1905.

WITNESSES:

m. c. Irv

UNITED STATES PATENT OFFICE.

FREDERICK W. PARSONS, OF TARRYTOWN, NEW YORK, ASSIGNOR TO INGERSOLL-RANDCOMPANY, OF NEW YORK, N. Y.

DRILL-BIT.

Specification of Letters Patent.

Patented Sept. 8,. 1908.

Toall whom it may comern:

Be it known that I, FREDERICK W. PAR- SONS, a citizen of the UnitedStates, residing at Tarrytown, in the county of Westchester and State ofNew York, have invented a certain new and useful Improvement in Drill-Bits, of'which the following is a specification.

This invention relates to improvements in the drill bits used inconnection with rock drills of either the pneumatic hammer, or thereciprocating piston t )e, in drilling holes in stone, rock, and the ile. In drilling stone the cutting edgesof the bit become dulled veryrapid and the bit has to be removed from time to time to bere-sharpened. The bits, of necessity, must be of considerable length,and in order that drilling operations may be continued withoutinterruption, the operator must be supplied with a number of the bits,to the end that he may have sufficient sharpened tools at hand to keepthe work going while the dulled bits are being redressed. The bulk andweight of this supply of extra bits must be carried by the operator tothe place of working and back and forth to the tool dresser.

It is my object, therefore, to provide a drill bit of the requiredlength, with short de tachable cuttin heads of small bulk andcomparatively ight weight, a supply of which can be carried by thedriller without inconvenience. This also avoids the expense of the longshank for each cutting head where the bits are all ofone piece. Inmaking such a jointed bit it. is essential that the parts be united sofirmly that they cannot come apart while the bit is in the hole, andthey also must be so coupled together that the cuttinghead will berotated with the shank in the operation of drilling. I attain m objectby constructing the drill bits in t e manner illustrated in theaccompanying drawings, in which Figure 1 shows in elevation one side ofm drill bit, with the cutting head detache Fig: 2, an elevation of thereverse side with the cutting head joined to the shank; Fig. 3, a sideelevation showing a modified form of the coupllaing joint; and Fig. 4,an end view.

of the s head.

Like letters of reference designate like parts in the several views.

A represents the shank of the .tool, which is made. of a length tocorrespond with the of the bit without the cutting depth of the holes tobe drilled. The up er end of the shank at B is formed to fit eit er thesocket in a drilling hammer, or the chuck end of the pistonin areciprocating drill. At the other end, the shank is provided with acollar and reduced portion C, upon which is sprung a split sleeve D ofspring steel, or other suitable metal, said sleeve before being sprungin place having a diameter somewhat smaller than the diameter of theshank at (J. The cutting head F is short, being of a length justsuflicient to carry the cutting edges or blades of the tool, and isprovided with'a shank G, which is adapted to be inserted in the sleeveD, and to abut when in place against the portion C of the'shank A. Thisshank G is of a diameter slightly larger than the inside diameter of thesleeve D, S?) that some force is required to insert. the shank in thesleeve. B reason. of this difference in diameter and t e elasticity ofthe sleeve, the sleeve will grip the shank G so firmly that it cannotbe-displaced while the bit is working its way into the hole that isbeing drilled, nor left in the hole when the shank is withdrawn. Tofacilitate the insertion of the shank G in the sleeve, the edges of thetwo will be slightly beveled.

In order to insure the rotation of the cutting head with the shank ofthe bit, I provide the sleeve D at each end with the pro'ecting tonguesE,whichengage slots H and i cut in the head F and in the collar on shankA, as shown in Fig. 2. 4

Other means for locking the shank and cutting head to the sleeve D maybe employed; as, for instance, the modification shown in Fig. 3, inwhich the shank and cuttin head are provided with tongues at J andspectively, which engage the groove formed by the split in the sleeve D.Some little force is required to withdraw the cutting heads F from thesleeve 1), but it can be'readily done by tools with which the drillerwill be sup lied.

It will be evident that by means of a drill bit constructed in the abovemanner there will be attained economy in the use of metal inconstructing the bits; inasmuch as one shank will suffice for use inconnection with a large number of cuttin heads, said cutting heads beingmade with different forms of teeth or cutting ed es, to conform with thework in hand, an furthermore, that said cutting heads will be so smallin bulk and light of weight that a quantity of them can be carried bythe driller without inconvenience.

Having thus described my improved bit, and without confining myself tothe particular means for cou ling the cuttin heads to the shank hereinescnbed, what claim as my invention and desire to secure by Letters APatent is 1. A drill bit comprising a shank having an elasticcylindrical metal sleeve projecting from one end, and a cutting headadapted to be forced into and out from the projecting end of saidsleeve.

2. A drill bit comprising a shank and a cutting head, the contlguousends of which are placed one against the other, in combination with anelastic cylindrical metal sleeve into the opposite ends of which theshank and head are forced to couple them together, and

means for preventing the rotation of said parts with reference to oneanother.

3. A drill bit comprisin a shank'and cutting head united by an e asticmetal sleeve spht longitudinally, into the op osite ends of which thetwo are forced, $8M? sleeve being also coupled to the shank and to thehead by tongue and groove joints.

In testimonywhereofl have aflixed my signature, in presence oftwo'witnesses.

FREDERICK W. PARSONS.

Witnesses:

M. E. VERBEcK, A. S. DIVEN.

